Groupfolders - E-Mail on favorites


we are using Nextcloud 20.0.5 and Groupfolders 8.2.0.
I´m trying to get the emailnotification only on a few folders in a groupfolder.

In the activity settings have i checkt the right checkbox to get the email notification if a file or folder on my favorites got changed but i dont get an email. Does this work recursive cause i only added one folder with many subfolders to my favorites ?

In the activity app i can see that a activity has bben created.

i hope someone can help me.